This web site is devoted to an investigation into the sound
and tuning of church bells. A specially developed software
package (Wavanal) has provided new results and insights both into
how bells produce the sound they do, and the factors affecting
the quality or timbre of a bell sound. Wavanal runs on a standard multi-media PC and yet allows more
detailed analysis than expensive spectrum analysers. The software is free and can be downloaded here. The site includes comparisons between numerous peals of bells, a brief history of bell tuning and a collection of classic papers on the subject.

The bell is one of the older, and certainly is the loudest of, musical instruments. The sound of a bell has the power to charm, to amaze, to warn, to frighten, and to lift the spirit. Bells are ubiquitous even in our electronic age. And yet the way in which a bell produces its sound is not well understood. Some of the results and conclusions reached were a surprise. When I began this investigation a decade ago, I assumed I would be studying inanimate objects - bells. It is now clear that psycho-acoustic effects - the way our ears work and the perception we have of sounds - are hugely important, and that some of the more important effects, such as the pitch or strike note we hear, are artifacts of our perceptive processes.

This website revisits some of the theories and research of the past, presents some new evidence, and uses the easy and flexible analysis permitted by Wavanal to support and supplement existing understanding. I have a collection of almost 6000 bell recordings, of many different founders and dates, to which I'm adding all the time. Analysis and comparison of them is continuing and will be uploaded as I complete it. If particular recordings are of interest, you have comments on the site, or you have good (or bad!) experiences with Wavanal, drop me an email.

To get around the site, use the contents list on the left. The 'next', 'previous' and 'up' links at the top of the pages will take you on a tour of the whole site.

What's New?

October 28, 2018:An analysis of the tuning of Westminster Abbey tenor in 1971 showing that it is not possible to tune the partials above the nominal independently.

July 29, 2018:
The text of a talk given in 1916 by William Wooding Starmer on carillons and chimes.

July 14, 2018:
An article on stretch tuning, with an explanation based on the effect of the upper partials on strike pitches. This article has since been updated with additional information from Mike Milsom and Chris Povey.

June 30, 2018:
A new release of Wavanal allowing selection of A=432Hz to help with analysis of Gillett & Johnston carillons tuned to this pitch standard.

July 12, 2012:
Move to new hosting company, as a precursor to a complete site redesign. Also, a maintenance release of Wavanal which has been around for a couple of years.

August 18, 2008:
Two new virtual pitch tests are in progress, filling in a gap in the research to aid the writing of a journal article. The experiments are now over, but thanks to those who contributed.

June 17, 2008:
Following award to me of a PhD, three introductory articles and the full text of the thesis are available here.

October 9, 2007:
NB The virtual pitch tests announced here are complete. The original accouncement read "You can be of enormous help to my bell acoustics research. All you need is a PC or MAC with sound, a broadband connection, and a musical ear. Follow the link for a set of experiments investigating the origin of the strike note and the effect different partials have on its pitch. I need as many people as possible to do these tests. There are nine different tests, and each one takes just a few minutes to carry out. Do help if you can."

October 9, 2007:
This website hasn't been updated for a while but the bell acoustics research is still very much in progress! As of today my collection of bell recordings comprises 2,130 bells, dating from 1285 to today, from 15 countries, at least 100 different founders, and nominals ranging over nearly 6 octaves. I am in the late stages of completing a thesis documenting some ground-breaking research into bell acoustics. Many people continue to use Wavanal, not least a team collecting bell tuning information for the UK National Bell Register.

October 24, 2004:
A slightly updated version 5.3 of Wavanal has just been uploaded. As well as the changes in version 5.2, the new version includes support for German note names, and allows A=435Hz as well as A=440Hz as a pitch standard. I have also uploaded a new version of Rounds which uses up to 16 bells, and allows the speed of the ringing to be changed.

October 15, 2004:
A new version 5.2 of Wavanal has just been uploaded. It is much better at finding partials from noisy recordings.

May 23, 2004:
I have added an additional 'recording' of Coventry, with the effect of tower acoustic added.

May 11, 2004:
To complement the details and simulation of the old Coventry bells, I have transcribed the account of the court case.

May 9, 2004:
An investigation into and simulation of the old bells at St. Michaels, Coventry, recast in 1926 but said in their time to be the finest ten in England.

April 25, 2004:
The section on The quality of a peal of bells has been completely re-written to take account of major recent advances in my understanding. The first page linked to includes a very brief summary of the various psycho-acoustic effects, including a new insight into our ability to distinguish intervals between partials.

December 15, 2003:
Ernst Terhardt's important paper on The Strike Note of Bells, published in 1984 but now translated into English for the first time, is published here with Prof. Terhardt's kind permission.

May 2, 2003:
New versions of Wavanal and Tuner and a brand new program, Rounds, have been uploaded. Also, I have now made some major breakthroughs in understanding and demonstrating how the pitch or strike note of bells arises, and in the effect of room acoustics on bell sound. Write-ups to follow ...

December 1, 2002:
The strike note of bells has been a puzzle of long standing. Building on the work of Terhardt, and Eggen and Houtsma, I have found a new way of analysing bell recordings which gives important insights into their pitch. It will be some while before my experiments are sufficiently complete to give a proper account. This note is by way of a warning that the page on strike notes will need substantial revision to reflect my latest understanding. I will be asking people to assist in further experiments as well.

October 30, 2002:
I have updated the page on taking bell recordings both to explain how to improve the quality of mp3 recordings, and to document recent experience of recordings with a professional condenser microphone.

October 12, 2002:
Additional significant information has come to light about the bells at Merthyr Tydfil and the description has been substantially re-written.

October 7, 2002:
I have uploaded a new program, Tuner, a PC-based spectrum analyser designed specifically to help with the tuning of bells.

September 29, 2002:
What is almost certainly (at at least four tons) the largest cast steel bell in the UK, at St Peter's Italian Church in London. This is a most unusual bell in a most unusual situation.

September 23, 2002:
A investigation into the bells at Merthyr Tydfil: a peal of great importance in Taylor's development of true-harmonic tuning.

January 3, 2002:
I have at last uploaded the spreadsheet I use to analyse the tuning of a peal of bells, available from here.

December 22, 2001:
Two significant new uploads to the site: an analysis of Great Paul, including an explanation of secondary strike which affects the sound of all big bells; and more work on simulating the sound of bells.

December 6, 2001:
In response to a request from John Ketteringham, I have uploaded all my recordings of bells rung in peal. A complete list now appears on the bell collection page.

November 10, 2001:
A new utility - Pitcher - allowing easy estimation of the pitch of bells and other tones, has just been uploaded.

October 16, 2001:
Details of the historical and interesting bells at Painswick in Gloucestershire.

October 13, 2001:
A major new release of Wavanal has been uploaded that can record and analyse bells direct from a PC or laptop microphone. The Wavanal page gives more information and a link to the detailed documentation.

September 20, 2001:
Two true-harmonic twelves, Llandaff and Tewkesbury, roughly the same weight, one from Whitechapel and one from Taylors. Are there material differences between them?.

August 19, 2001:
A glossary of terms has been added to the contents list at the left.

August 18, 2001:
Some French bells, at Vieillevie and La Vinzelle, demonstrate how continental bellfounders in the 19th century were producing true-harmonic bells, unlike the UK foundries.

April 11, 2001:
Analysis of Newcastle Cathedral just complete. Three years before Simpson published his findings, Taylors were well on the way to true-harmonic tuning.

April 7, 2001:
Does the tuning of the prime affect the pitch of a bell? See a recent investigation that suggests it might.

March 17, 2001:
A new build of Wavanal has been uploaded that works with compressed .wav and .mp3 files (to save disc space). The Wavanal page gives more information and a link to the detailed documentation.

March 1, 2001:
More peals of bells recorded - including a peal of steel bells.

January 17, 2001:
Version 3.2 of Wavanal (with a couple of new facilities) uploaded. Also, several analyses of bells have been put on the site and more are appearing as quickly as I can write them.

January 3, 2001:
Updated list of bell recordings, and added further information to the section on octave stretch.